Title Reports.  They may seem like an unnecessary expense, but I wholly endorse having a current Title Report on a property before Design work gets underway, and definitely before construction begins.  Here are two good reasons to have a current Title Report:

1.  Utility Easements and setbacks - yes, this is probably the most obvious reason to have a current Title Report.  It is important to determine what portions of a parcel are free of utility easements and setbacks required by the local authorities and utility companies.  You may be surprised at what legacy utility easements exist on the property being developed.  Those easements can greatly restrict your plans for developing a site, but it is better to find that out earlier rather than later.

2.  Verified Property Lines - as incredible as it may sound, I once worked on a school project where only half of the property was actually owned by the school district that was building a small alternative classroom building on it.  The project progressed past the structural phase (steel, in this case), and then came abruptly to a halt when the true property owner filed a trespassing notice.  The project was put on hold for six months while the purchase of the property was worked out between the parties.  In addition to the purchase cost of the property, there were substantial construction delay and re-work costs.  In this instance, a current Title Report would have been cheap insurance compared to these costs.